The effect of montelukast on wheal reactions in skin prick tests: a double-blind-placebo-controlled randomized trial.

OBJECTIVE It is well-known that number of drugs may interfere with wheal reactions in skin prick test. However, the effect of long-term use of montelukast, a cystenil leukotriene receptor antagonist, on skin prick test hasn't been full elucidated. The aim of present study was to demonstrate the effect of montelukast on skin prick tests (SPT). METHODS This is a single-center, randomized, double-blinded, placebo-controlled study including two treatment periods with a wash-out interval. The subjects received montelukast (5 mg per day), fexofenadine HCl (60 mg per day) and placebo (lactose) with a double-blinded manner during 7- and 21-days treatment periods with a 14 days wash-out period. Dermatophagoides farinae (D. farinae) was used as the skin test material, while histamine as positive control and normal saline as negative control. Overall, 7 skin prick tests were performed at following time points: before treatment periods, on the last days of both treatment periods, 24 h after completion of treatment periods, and on the last day of 14-days interval. RESULTS Sixty house dust mite (HDM) allergic children (23 girls and 37 boys) with allergic rhinitis and/or asthma completed the study. Mean age was 8.3 ± 2.0 years. In the fexofenadine group, a significant suppression was observed in post-treatment values when compared to baseline values in SPT with D. farinae (p = 0.019). In the montelukast group, no significant suppression was observed in SPT with D. farinae at all time points when compared to baseline. CONCLUSIONS Our results showed that montelukast had no effect on measurements of SPT. Thus, we concluded that there is no need to discontinue the treatment in order to perform SPT in patients receiving montelukast, even in those on montelukast treatment for at least 21 days.